Various configurations have been utilized to enhance efficiency of thin film inductive transducers used for recording magnetic transitions on a moving magnetic recording medium.
U.S. Pat. No. 3,700,827 discloses a thin film magnetic head with a yoke structure that narrows from a back region to a pole tip region. A separate magnetic core interconnects the yoke pieces at the back region. A wire coil encircles the magnetic core for activating the pole pieces during recording and transmitting electrical pulses activated in the coil during reading of magnetic transitions from a magnetic recording medium.
U.S. Pat. No. 4,016,601 discloses an integrated magnetic head assembly wherein the pole pieces have a reduced width in the pole tip region and a flat conductor winding coil has a branch inserted between the pole piece layers. The reduction in width in the pole tip region is achieved by etch removal of concave portions of the substrate and pole pieces, such that the distance between the end of the pole tip and the wide portion of the yoke structure is greater than the thickness of one of the magnetic layers plus the magnetic gap.
U.S. Pat. No. 4,190,872 provides a pole tip region of preselected constant relatively narrow width comprising two thin magnetic layers that extend in a direction normal to the magnetic medium. The effects of spurious signals from adjacent tracks on the medium are minimized by having the pole tip region extend a distance at least 5/D, where D is the recording density. The cross-sectional area of the yoke structure in the back region is progressively increased in width rearward of the pole tip region.
In U.S. Pat. No. 4,190,872, the non-magnetic layer separating the first and second layers of magnetic materials is deposited directly on the first layer of magnetic material. It has also been proposed to deposit the non-magnetic layer between the second insulating material and the second layer of magnetic material. However, these techniques have been plagued by poor adhesion of the non-magnetic material and chemical attack of the coils and lap straps.